A bumper of a motor vehicle is provided on the front or back of an automobile to lessen the shock or damage when it hits anything. Inside of the bumper, a bumper reinforcement is provided to strengthen and support the activity of the bumper. Conventional bumper reinforcements to absorb the impact upon collision on automobiles are illustrated in FIGS. 1 to 5.
FIG. 1 is an exploded perspective view of a bumper (1) for an automobile and a reinforcement (10) therefor, wherein the bumper reinforcement (10) is provided behind the bumper (1) to give an additional support to the bumper (1) upon collision.
FIG. 2 is a partial sectional view of the conventional bumper reinforcement, and FIG. 3 is a rear perspective view showing a part of the conventional bumper reinforcement.
The conventional bumper reinforcement (10) comprises a body (12) with a vertical section in the shape of “” and towers (14) provided at both side ends of the body (12) and having vertical lateral surfaces (16).
Each of the towers (14) is mounted on a body frame of a vehicle (not shown) at its base plate and serves to buffer the pressure and tension from the bumper (1) generated upon collision and prevent the impact and the pressure and tension from being directly transmitted to the body frame.
In case of collision, the deformation and breakage due to the impacts of the collision most frequently occurs in a part where the lateral surfaces of the towers (14) and the body (12) are connected as shown in FIG. 3.
Therefore, in case of a head-on collision or a broadside collision of an automobile, the bumper reinforcement (10) with the towers (14) as above becomes twisted and deformed due to the force transmitted to the part ‘A’ of FIG. 3. In this case, since the deformation is permanent, even for a weak collision, the entire bumper should be replaced with a new one.
In order to solve these problems, an improved bumper reinforcement has been suggested in Korean Patent No. 340464.
As shown in FIGS. 4 and 5, a slant part is provided at a connecting part between a body and towers of the bumper reinforcement, so that the deformation upon collision can be minimized and the permanent deformation can be decreased, thereby extending the life span of the bumper.
That is, since such bumper reinforcement was formed slant at the connecting part, and since a slant surface (20) of the connecting part supported a upper plate (18) and a lower plate (19) in the middle as shown in FIG. 5, the connecting part became strengthened and more resistant against the impacts.
However, the connecting part could not absorb the force for deformation sufficiently. Therefore, if an impact over the limit was given to the bumper, a part of the body (D) of the bumper reinforcement became damaged and consequently the collision energy to be absorbed by the bumper reinforcement decreased.
Further, since the respective ends of the upper and lower plates (18 and 19) of the conventional bumper reinforcement was in linear contact with the bumper, rather than a surface contact, if the collision occurred, one ends of the respective upper plate (18) and lower plate (19) were pressed and bent upon the bumper, and thus they became damaged.